|IV Dose||Any IV dose should be 75% of corresponding oral dose (see below)|
|Oral dose||Dosing guidelines are largely a theological issue among pediatric cardiologists.|
Total oral digitalizing dose (TDD) given over 24 hours:
Prematures: 20 ug/kg
Full term newborns: 30 ug/kg
Infants < 2years: 40-50 ug/kg
Children >2 years: 30-40 ug/kg
Adults: 1.25-1.5 mg total dose.
Maintenance: 25% of TDD, daily divided BID.
|Levels||Life is too short to argue about whether digoxin levels are meaningful, other than in suspected toxicity.|
Column-separated levels in infants.
O.7-2.0 nanograms/ml in adults.
Levels up to 3.5 are well tolerated in infants
|Kinetics||Infants and children have high volumes of distribution.|
Elimination half-life by age:
Prematures: 61 hours.
Full term newborns: 35 hours
Infants: 18 hours.
Children: 37 hours.
Adults: 35-48 hours.
|Cautions||Most common arrhythmias due to toxicity are PVCs and VT in adults, PAT with block in children|
|Interactions||Levels increased by erythromycin, quinidine, amiodarone, verapamil and aldactone. (!) Levels decreased by phenytoin. Digoxin toxic arrhythmias exacerbated by bretylium due to initial catechol release from nerve terminals|
|Preparations||Lanoxin scored tablets: 0.125, 0.250. 0.500 mg|
Lanoxicaps (solution in capsule): 50, 100, 200 ug.
Lanoxin elixir (60 cc dropper bottle): 50 ug/ml.
Lanoxin injection, Adult: 500 ug/2 ml
Pediatric:100 ug/1 ml
|FDA approval in children||One of the few!|